<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
   <script>
       var person = "张三";
       var person = "李四";
       var a = 12;
       console.log("person="+person);
       console.log("a="+a);
   </script>
</body>
</html>